A prisoner plotted to kill Justin Bieber after he didn't reply to his letters

A prisoner infatuated with pop star Justin Bieber plotted to castrate the singer with hedge clippers and strangle him.

Court documents recently filed in New Mexico reveal Dana Martin told investigators he persuaded a man he met in prison and the man's nephew to kill the Canadian singer, along with Bieber's personal bodyguard and two others, and castrate two of the victims with hedge clippers.

Martin, a Vermont man who is in prison in Albuquerque, New Mexico serving two life sentences for the 2000 killing of a 15-year-old girl, said he was angry at Bieber because he didn't respond to any of his letters.

"This perceived slight made Mr Martin upset and that, coupled with Mr Martin's perception of being a 'nobody' in prison, led him to begin plotting the kidnap and murder of Victim 3," court documents said.

The documents identified Victim 3 as "J.B.," which New Mexico State Police spokesman Lt Robert McDonald later confirmed was Bieber.

Martin told investigators that Mark Staake and Tanner D Ruane headed from New Mexico to the East Coast, planning to be near a Bieber concert scheduled in New York City after killing and castrating two others. They missed a turn and crossed into Canada from Vermont.

Clinton Norris, of the New Mexico State Police investigations bureau, said in an affidavit that Martin instructed the suspects to strangle the two first intended targets with paisley neckties, the same kind used in his 2000 murder case.

The targets of the castration plot were not connected to Bieber, authorities said, and it did not appear that the pop singer was ever in immediate danger.

In a statement Bieber's management said: "We take every precaution to protect and ensure the safety of Justin and his fans."